Medicine is becoming less invasive and more personalized. For example, a patient presenting with a mass in the lung or pancreas is not necessarily scheduled for surgery to characterize the lesion as neoplastic or not. Instead, a minute sample of cells from the lesion is obtained through a procedure called a fine needle aspiration (FNA), which involves aspirating cells with a small needle after it is localized to the site of interest with the aid of CT scan and/or ultrasound. When performing FNA, either no incision is made, or the biopsy site is inconspicuous, similar to a puncture wound following a blood draw, which allows for outpatient procedures and prevents need for hospitalization. By examining cells under a microscope, pathologists render diagnoses of benignity or malignancy. At one time, there were limited treatment options and diagnoses of malignancy made on smears would suffice and treatment would ensue. Nowadays, ancillary tests afford greater information about the tumor and therapeutic options that are likely to be more effective. Though minimally invasive procedures and personalized treatment options provide better patient care, imparting greater levels of information on even smaller tissue samples is challenging and places a greater burden on pathologists and consequences for patients.
Ancillary tests to answer the pertinent questions are frequently conducted on cell blocks, pellets of cells formed from the FNA sample, if available. Currently, there is no accepted laboratory standard on the preparation of cell blocks, though labs frequently employ one of several “homebrew” methods. When samples are large, cell blocks are easier to form, but with smaller samples, the “homebrew” methods may fail or result in a suboptimal cell block. Thus, there is a growing need to develop a standardized apparatus and method for preparing cell blocks in a low cost and efficient manner to provide answers to clinicians that impact therapeutic decisions.